Steam generator



Aug. 31, 1943. N. G. sANDsTRoM STEAM GENERATOR Filed De'c. 19, 1959OOOOOOOOO 2A sheets-sheet 1 IN V EN TOR.

A TTORNEYS.

Aug. 31, 1943. N. G. sANDs'rRoM 2,323,530

STEAM GENERATOR Filed 1390.19,- 1959 2 sheets-sheet 2- a I, l i 4,

i m'll tNVENTOR. B, 77E/19W@ A TTORNEYS.

Patented Aug. 31, 1943 :STEAM GENERATOR Nils Gustave .Sandstron'n Erie,Pa., assignor to Erie City Iron `Works, Erie, Pa., a corporation ofPennsylvania Application December 19, 1939, Serial No. 309,996

8 Claims.

This 4invention embodies an `'improvement in Isteam generators of theYlongitudinal Idrum, vertical Water tube'type. `"lliegenerator isself-contained and .provides 'a Water cooled furnace, and is providedwithaself-contained case. 'This includes a .furnace having Aa combustion`chamber and .a Aconvection `chamber `which Aare .preferably separatedbya bridge wall, the convection rchan ber being filled with water tubesextending from a longitudinal .upper steam and water drum, tending the(full 'length ofthe furnace to a lower drum, the lower ldrum terminatingat :the I:front end .of Vthe Aconvection chamber.

`The invention involves a system of 'water tubes forming the walls ofthe combustion chamber, these tubes fbeing arranged in a v'downccrnerbank and an upcomer bank, the -downcomer bank `being outside the upcomerbank of tubes. These inner and outer sets of -tubes lead to a headerextending along the -sides `of the combustion chamber at or near thebottom, and these rtwo banks provide a. circulation originating andterminating in the Water space of the uppersteam and water drum. Thedowncomer tubes lead from a portion of the upper drum yseparated Afromthe `mainbody thereof so that the circulation may be more ldeiinitelycontrolled.

Oneof the major features of -the invention is this arrangement of thewater wall for the `combustion chamber. Other features and details ofthe invention will appear `from the specification and claims. Y f

A preferred embodiment of .the invention is illustrated in theaccompanying drawings as follows:

Fig. 1 shows a central vertical section of one modification of theboiler on the line I-I in Fig. 2.

Fig. l2 shows at its left side a section on the line 2 2 in Fig. 1, andat its right side a section on the line Za-Za in Fig. 1.

Fig. 3 shows a section on the line 3-'3 in Figs. 2 and 4.

Fig. 4 shows .a side elevation of the lower part of the `combustionchamber wall including clinker chills.

Fig. 4a a section on the .line lla-4a .in Fig. 2.

Fig. 5 a central section of a modification, the modification beingadapted to burn fine or liquid fuel, the section being on the line 5 5in Fig. 6.

Fig. 6 a section on the line 6-'6 in Fig. 5.

Fig. "7 .a central section `of `a modication designed to accommodate aninclined Stoker.

Fig. 8 a detached view showing the cooling tubes `arranged on the bridgeWall.

In the modification shown in Fig. l, I -marks airupper drum, 2 a Ylowerdrum, 3 a'cornbustion chamberJ 'a bridgewall, 5 `a convection chamberseparated `from thefcombustion chamber by thIe bridge wall. Water tubesi6 connect the upperand rlower drums -and practically ll ithe convectionchamber.

The side walls of the `convection chamber has a yrefractory (I ofordinary formwvhich ,is `continued `over the upper drum by insulation '8in the usual imanner. The side refractory I andinsulation la issupported by a steel structure 9. A 4steel lcasing II) is arranged atthe side of :the insulating material and `this is supported `andlncluded `in fa ygeneral frame o'f structural `steel :I I.

-Afbaile yIl formed of refractory material lis arranged along one bankof tubes giving Aa downpass at the entrance of gases to the convectionchamber. Bafes I3 and I4 of steel are provided at the rear rof the'convection Vchanfiber giving an up Iand down pass to the gases. Thegases .fare dischargedthrough a gas outlet `I5 which is arranged `at theside of the upper drum.

The combustion chamber is provided at each side 'with a Water wall. Thisis accomplished by downcomer tubes I5 extending from the upper drum. Theinlets of these downcomer tubes are separated -from the main portions of`thedrum by-albafe plate I1. The'lower ends of the tubes F6 lead toaheader IiLand upcomer tubes `I-' `extend from the header in the furnaceside wall to the water space of the upper drum. The tubes I9 -are backed'up by `refractory blocks 20 and insulation 22. Channel iron lowerblocks 2l "are for chilling the clinker at the sides of the ifurnace.`

Insulation 22 encloses the downcomer tubes I"6 and thesteel case .I0extends over the insulation in a :manner similar to that of theconvection chamber and is supported by the surrounding frame lI I. Itwill be understood that the water Wall is duplicated at both sides ofthe combustion chamber.

The front wall 23 of the combustion chamber is of refractory materialand here again the case I0 extends `outside of the wall and the frame'for the casing supports the lfront end of the upper drum, and has a4furnace opening 24 through which the furnace is red.

The water level is maintained at substantially the medial line oi theupper -drurn and steam outlets `are taken through nozzles 25 and Thewater is fed through opening 21.

The independent circulating .system forming the walls of .the combustionchamber take wateil from the upper drum which is comparatively clean sothat the headers i8 are subjected to almost no accumulation of sediment.The distribution of this circulation throughout the length of thecombustion space is very uniform, the flow resistances and freedom ofcirculation being actly the same for all the tubes throughout thesystem. This rapidity or freedom of circulation assures practicallywater filled tubes throughout the system, thereby extending the life oithe tubes and promoting their eiliciency.

The circulation in the convection chamber is generally downward at'therear of the convection chamber and upward at the forward portion of theconvection chamber where the tubes meet the incoming hotter gases. Thesystem lends itself very well to an integral or self-contained generatorunit.

In Figs. 5 and 6, 3i marks an upper drum, a lower drum, 33 a combustionchamber, 35, a convection chamber, 35 a bridge wall, the bridge wallbeing extended forming a roof 35 of the forward end of the furnace. Thefront wall 3l of the furnace has an opening 38 for the introduction offuel. Water tubes 3S connect the upper and lower drums. The water wallat each side of the combustion chamber is formed by the downcomer tubes'lil and upcorner tubes lill leading from and to the upper drum andconnecting it with a header 42 extending the full length of the setting.The end wall of the combustion chamber has the downcomer tubes fito andupcomer tubes fila leading from and to the water space of the upper drumand connecting it with a cross header 42o. These water Walls areotherwise insulated and encased as in the structure shown in Fig. l.

A cross header 43 extends across the end wall 31 and cooling tubes 44extend along the furnace arch 36 and over the lower part of the bridgewall to the lower drum, thus effecting a cooling circulation along thearch and bridge wall. Header 43 is fed by tubes 45 connecting to thelower drum 32.

The convection chamber is baiiled as in Fig. 1, and the watercirculation and steaming characteristics are similar to those in Fig. l.

The modication shown in Figs. 7 and il comprises an upper drum A1, alower drum 4t, cornbustion chamber 49, convection chamber 5G, a frontwall 5| having a stoker opening 52 and an inclined stoker The water wallof the combustion chamber is formed of tubes 54 and 55 which extend fromthe upper drum to a header 56 along the sides of the combustion chamber.This water wall is similar to that of Fig. l and similarly insulated andencased.

A bridge wall 51 separates the combustion and convection chambers andthis wall extends below the lower drum. Tubes 58 and 59 extend from thelower drum through and along the lower part of the bridge wall to across header Bil. The cross header is connected by tubes 6i with thelower drum 48.

The furnace, as a whole, is encased and insulated substantially as inthe structure shown in Fig. l, and the circulation and steam generationfollows the same general plan.

By placing the upcomer tubes as well as the downcomer tubes in the upperdrum to the water space, the agitation at the water level is decreasedso that the steam discharged may carry less moisture. Also by connectingthe upcorner tubes from the cross headers at the front below the waterlevel, this also assists in reducing the agitation and consequentlyprovides a drier steam. To the same end the circulation from the crossheader at the arch or bridge wall is returned to the lower drum andtherefor the agitation with relation to this circulation is removed fromthe upper drum and tends to reduce the agitation.

It will be noted, however, that the entire heat exchange is carried intothe liquid in its circulation, also the circulation is definitelycontrolled so that the steam gradually generated approaches the portionof the upper drum over the combus- 'ion space. What I claim as new is:

l. In a steam generator, the combination of a furnace having side walls;an upper steam and water drum extending longitudinally and horizontallyalong the top of the furnace; a lower water drum shorter than the upperdrinn providing furnace space under the upper drum and at the end of thelower drum; circulating tubes connecting the drums; and headers alongthe sides of the furnace wall, each side having an inner and outer setof circulating tubes connecting the headers and the water space of theupper drum, the inner tubes cooling the walls, the outer set ofcirculating tubes being embedded in the wall.

2. In a steam generator, the combination of a furnace having side wallsand comprising a combustion chamber and a convection chamber; an uppersteam and water drum extending longitudinally and horizontally along thetop of the combustion and convection chambers; a lower water drum in theconvection chamber; circulating tubes connecting the upper and lowerdrums in the convection chamber; headers along the side walls of atleast the combustion chamber; and an inner and outer set of circulatingtubes connecting each header and the water space of the upper drum, eachinner set of tubes cooling the side wall, the outer set of circulatingtubes being embedded in the wall.

3. In a steam generator, the combination of a furnace having side wallsand comprising a ccmbustion chamber and a convection chamber; alongitudinally extending upper steam and water drum in the combustionand convection chambers; a lower water drum in the convection chamber;circulating tubes connecting the upper and lower drums in the convectionchamber; headers along the side walls of at least the combustionchamber; inner and outer sets of circulating tubes connecting eachheader and the water space of the upper drum, each inner set of tubescooling the side wall; a cross header below the lower drum; tubesextending from the lower drum adjacent the combustion chamber to thecross header; and tubes connecting the cross header with the lower drum.

4i. In a steam generator, the combination of a furnace having sidewalls, said furnace comprising a combustion chamber and a convectionchamber, said chambers being separated by a bridge wall; alongitudinally extending upper steam and water drum in the combustionand convection chambers; a lower water drum in the convection chamber;tubes in the convection chamber connecting the upper and lower drums;headers along each side wall of at least the combustion chamber; aninner and outer set of tubes connecting each header with the water spaceof the upper drum, the inner tubes of each set coeling the side wall; across header to the rear ci the combustion chamber; bridge wall coolingtubes connecting the lower drum with the cross header; and tubesconnecting the cross header with the lower drum.

5. In a steam generator, the combination of a furnace comprising acombustion space, a convection space, side and end walls, and a furnacearch below the convection space; a longitudinally extending upper steamand water drum in the combustion and convection spaces; a lower waterdrum above the arch in the convection space; tubes in the convectionspace connecting the upper and lower drums; a cross header adjacent theouter end of the arch; cooling tubes extending from the lower drum alongthe arch to the cross header; and tubes connecting the cross header`with the lower drum.

6. In a steam generator, the combination of a furnace comprising acombustion space, a convection space, side and end walls, and a furnacearch below the convection space; a longitudinally extending upper steamand water drum in the combustion and convection spaces; a lower waterdrum above the arch in the convection space; tubes in the convectionspace connecting the upper and lower drums; a cross header adjacent theouter end of the arch; cooling tubes extending from the lower drum alongthe arch to the cross header; tubes connecting the cross header with thelower drum; headers along each side wall of the furnace; and an innerand outer set of tubes connecting each header with the water space ofthe upper drum, the inner tubes cooling the side wall.

7. In a steam generator, the combination of a furnace comprising acombustion space, a convection space, side and end Walls, and a furnacearch below the convection space; a longitudinally drum above the arch inthe convection space; tubes in the convection space connecting the upperand lower drums; a cross header adjacent the outer end of the arch;cooling tubes extending from the lower drum along the arch to the crossheader; tubes connecting the cross header With the circulating system ofthe generator away from the upper drum; headers along each side wall ofthe furnace; an inner and outer set of tubes connecting each header withthe water space of the upper drum, the inner tubes cooling the sidewall; a cross header along the outer wall of the combustion space; andan inner and outer set of tubes connecting the last-mentioned crossheader with the Water space of the upper drum, the inner set of tubescooling the end wall of the combustion space.

8. In a steam generator, the combination of a furnace having side wallsand comprising a combustion and convection space, the combustion spacehaving a rear wall topped with a bridge wall; a longitudinally extendingupper steam and water drum in the combustion and convection spaces; alower drum in the convection space; tubes connecting the upper and lowerdrums; headers along the side wall; an inner and outer set of tubesconnecting each header and the water space of the upper drum, the innertubes cooling the side wall; a cross header to the rear of thecombustion space; cooling tubes extending from the lower drum along therear wall to the cross header; and tubes connecting the cross header tothe lower drum.

NILS G. SANDSTROM.

